The overall objectives are to characterize the sperm enzyme phosphoglycerate kinase B (PGK-B) immunogenetically and immunochemically and to determine its role in reproduction. In the coming year, we will continue to produce antisera against PGK-B and its somatic counterpart, PGK-A. We will proceed in our collaboration with Professor Goldberg at Northwestern University to refine further our technique for localizing the PGK isozymes in mouse testis sections by immunohistochemical techniques. We will complete our experiments involving the use the sex-reversed (Sxr) mice to determine the timing of PGK-B production during spermatogenesis in relation to production of the well-characterized sperm isozyme LDH-X. We will search for PGK-B activity in oocytes and tumors by electrophoretic techniques. Finally, we will continue to use the Pgk-2 gene as a marker to map other genes linked to major histocompatibility complex (MHC) in mice and to study the organization of genes around the MHC of mice and other mammals.